DE102022110496B4 - Switching device - Google Patents

Abstract

A switching device (100) has at least one fixed contact (2) projecting into a switching chamber (11) with a fastening part (20) attached to the switching chamber and a connecting part (21) projecting into a recess (200) of the fastening part and at least one of the following Characteristics:
- the connecting part (21) and the fastening part (20) are made of the same material, the fastening part (20) has a lower hardness than the connecting part (21);
- The connecting part (21) has a connecting element (211) formed by a stud bolt and a support element (213) with a bottom (215) for resting on the fastening part, which has an edge region (203) with a top (204) on which the underside (215) rests, with a connecting material (25) with a soft solder being between this and the upper side (204) and/or the support element (211) being welded to the edge region (203) and/or the edge region (203). has a fastening edge (205) integrally connected to the switching chamber (11);
- the connecting part (21) is screwed with a connecting element (216) with an external thread (217) into the recess (200) with an internal thread (207), one of the two having an interference fit before screwing in;
- A connecting material (24) with a soft solder is arranged in the recess (200) below the connecting element (211).

Description

A switching device is specified.

The switching device is designed in particular as an electromagnetically acting, remotely operated switch that can be operated by electrically conductive current. The switching device can be activated via a control circuit and can switch a load circuit. In particular, the switching device can be designed as a relay or as a contactor, in particular as a power contactor. Particularly preferably, the switching device can be designed as a gas-filled power contactor.

A possible application of such switching devices, in particular power contactors, is the opening and disconnecting of battery circuits, for example in motor vehicles such as electrically or partially electrically operated motor vehicles. These can, for example, be purely battery-operated vehicles (BEV: “Battery Electric Vehicle”), hybrid electric vehicles that can be charged via a socket or charging station (PHEV: “Plug-in Hybrid Electric Vehicle”) and hybrid electric vehicles (HEV: “Hybrid Electric Vehicle”). be. As a rule, both the plus and minus contacts of the battery are separated using a power contactor. This separation occurs in regular operation, for example when the vehicle is at rest and also in the event of a malfunction such as an accident or the like. The main task of the power contactor is to de-energize the vehicle and interrupt the flow of current.

A contactor usually carries high currents during operation. These are usually transmitted via supply lines such as copper rails, so-called bus bars, or other supply lines that are mounted on the contacts of the contactor that can be contacted from the outside, which can also be referred to as pole contact points or terminals. The copper bars or other supply lines can have cross sections of over 200 mm ² . In order to ensure sufficient, i.e. low-resistance, electrical contact, the supply lines must be mounted with sufficiently high tightening torques, which places high mechanical demands on the pole contact points of the contactor. In addition, shear forces and leverage forces can occur at the contact points during assembly and later operation. The contact points should therefore be made from a particularly hard but electrically conductive material.

Particularly powerful contactors have switching chambers made of ceramic materials, into which the contacts are soldered with hard solder at high temperatures of more than 800°C. However, this process carries the risk that the material properties of most electrically conductive materials that can be used for the contacts change and the material becomes softer. Adequate fastening of supply lines is then no longer possible without any problems.

To avoid this problem, materials can be used that are still sufficiently hard after the soldering process to withstand the stress. However, this usually leads to an increase in the price of the base material used, since, for example, special copper alloys have to be used. Furthermore, it is also known to integrate busbar pieces into a contactor, through which additional, spatially relocated attachment points can be made possible. However, this has disadvantages, for example high costs due to additional components, a higher final weight of the contactor and an increased electrical transition resistance from attachment point to attachment point.

The publication JP 2005 - 038 706 A describes a switching device that has fixed contacts that are formed by cup-shaped parts with screwed-in screws. The publication JP H11 - 232 986 A describes a switching device that also has fixed contacts that consist of cup-shaped parts with screwed-in screws. The publication US 2008 / 0 122 562 A1 describes a relay with two-part fixed contacts. The publication US 2016 / 0 012 995 A1 describes a switching device with fixed contacts that are also designed in two parts, with peg-shaped parts being screwed into cup-shaped parts. The publication DE 10 2019 129 805 B3 describes a plug connection between a contact pin and a contact socket.

At least one object of certain embodiments is to provide a switching device.

This task is solved by the subject matter according to the independent patent claim. Advantageous embodiments and further developments of the subject matter are characterized in the dependent claims and also emerge from the following description and the drawings.

According to at least one embodiment, a switching device has at least one fixed contact. The at least one fixed contact can in particular be provided and set up to provide an electrical supply line to a load circuit that is fed through the switching device The device should be switched on, i.e. closed, and switched off, i.e. disconnected.

Furthermore, the switching device can have at least one movable contact. The movable contact can in particular have or be a contact bridge. In other words, the contact bridge can be a movable contact of the switching device or part of a movable contact of the switching device. Properties and features of the movable contact described below can therefore be corresponding properties and features of the contact bridge and vice versa.

The at least one fixed contact and the at least one movable contact are intended and set up to switch on and off a load circuit that can be connected to the switching device. The movable contact, i.e. in particular the contact bridge, can be moved in the switching device between a non-connecting state and a curing state of the switching device in such a way that the movable contact, i.e. in particular the contact bridge, is separated from at least one fixed one in the non-connecting state of the switching device Contact is spaced apart and therefore galvanically isolated and in the switching state has a mechanical contact to the at least one fixed contact and is therefore galvanically connected to the at least one fixed contact. In the following, the through-switching state is also referred to as the switched-on state of the switching device, while the non-switching state is referred to as the switched-off state of the switching device.

Particularly preferably, the switching device has at least two fixed contacts, which are arranged separately from one another in the switching device and which are electrically conductive in the manner described above depending on the state of the movable contact, i.e. in particular the contact bridge, through the movable contact, i.e. in particular the contact bridge can be connected to each other or electrically separated from each other. The contact bridge preferably has an upper side with at least one contact area and an underside opposite the upper side. In the switching state of the switching device, the at least one contact region of the contact bridge is in mechanical contact with the at least one fixed contact, in particular a contact region of the at least one fixed contact. If the switching device has, for example, two fixed contacts, the contact bridge can accordingly have two contact areas. Features described below for a fixed contact can apply to several fixed contacts and particularly preferably to each fixed contact of the switching device.

Below, the general term “contacts” can refer in particular to all fixed contacts as well as the contact bridge. In particular, the contacts can have or be made of a metal, preferably copper or a copper alloy. Furthermore, at least for the contact areas, a composite material in the form of a metallic matrix material, preferably with or made of copper, and particles distributed therein, preferably with or made of a ceramic material such as aluminum oxide, is also possible.

According to a further embodiment, the switching device has a housing in which the movable contact and the at least one fixed contact or the at least two fixed contacts are arranged. The movable contact can in particular be arranged completely in the housing. The fact that a fixed contact is arranged in the housing can mean in particular that at least the contact area of the fixed contact, which is in mechanical contact with the movable contact in the switching state, is arranged within the housing. To connect a supply line of a circuit to be switched by the switching device, a fixed contact arranged in the housing can be electrically contacted from the outside, i.e. from outside the housing. For this purpose, a part of a fixed contact arranged in the housing can protrude from the housing and have a connection option for an electrical supply line outside the housing.

According to a further embodiment, the contacts are arranged in a gas atmosphere in the housing. This can mean in particular that the movable contact is arranged completely in the gas atmosphere in the housing and that furthermore at least parts of the fixed contact or contacts, such as the contact area or areas of the fixed contact or contacts, are arranged in the gas atmosphere in the housing. The switching device can accordingly particularly preferably be a gas-filled switching device such as a gas-filled contactor.

According to a further embodiment, the switching device has a switching chamber. The switching chamber can in particular be arranged within the housing. In particular, the switching chamber has an interior space. The contacts, that is to say the entire movable contact as well as part of the at least one fixed contact, are in the interior of the switching chamber arranged. The at least one fixed contact thus projects into the switching chamber. The at least one fixed contact projects in particular through an opening into the interior of the switching chamber. In other words, the at least one fixed contact is located partly inside the switching chamber and partly outside the switching chamber. For example, the switching chamber can have a switching chamber floor. The switching chamber can also have a switching chamber cover, which can enclose the interior together with the switching chamber floor. At least in the area in which the at least one fixed contact projects into the switching chamber, the switching chamber is made of a ceramic material, for example with or made of aluminum oxide. For example, the at least one fixed contact can protrude through an opening in the switching chamber cover. In this case, the switching chamber cover is preferably made of ceramic material.

A gas, i.e. at least part of the previously described gas atmosphere, can be located in the switching chamber. The gas can preferably have a proportion of at least 20% H ₂ and preferably at least 50% H ₂ . In addition to the hydrogen, the gas can contain an inert gas, particularly preferably N ₂ and/or one or more noble gases.

According to a further embodiment, the movable contact in the switching device can be moved by means of an axis. In particular, the movable contact can be movable, for example, by means of a drive that has the axis, wherein the drive can be designed in the form of a magnetic drive with a magnet armature or in the form of a motor drive. The axis can be connected at one end to the movable contact in such a way that the movable contact is movable by means of the axis, i.e. is also moved by the axis when the axis moves. The axis can in particular protrude into the interior of the switching chamber through an opening in the switching chamber. In the case of a magnetic drive, the magnet armature can be movable through a magnetic circuit in order to effect the switching operations described above. For this purpose, the magnetic circuit can have a yoke that has an opening through which the axis of the magnet armature protrudes. The axle can preferably have or be made of stainless steel. The yoke can preferably have or be made of pure iron or a low-doped iron alloy.

According to a further embodiment, the at least one fixed contact has two parts which, when put together, essentially form the at least one fixed contact. The two parts are permanently joined together in the switching device. Particularly preferably, the two parts are permanent and are therefore joined together in such a way that they cannot be separated from one another under normal operating conditions. Furthermore, the at least one fixed contact can have one or more connecting materials that can improve a permanent connection of the two parts.

In particular, the at least one fixed contact has, as the two parts, a fastening part and a connecting part, which, when joined together, essentially form the at least one fixed contact, for example except for at least one connecting material. Particularly preferably, the connecting part and the fastening part are connected to one another at least in a form-fitting and/or non-positive manner, for example by a clamp connection or, particularly preferably by a screw connection. Furthermore, the connecting part and the fastening part can also be connected to one another in a materially bonded manner.

The fastening part is intended and designed to be fastened to the switching chamber, so that the at least one fixed contact is fastened to the fastening part on the switching chamber. In particular, the fastening part can be connected to the switching chamber in a materially bonded manner. The connection part is intended and set up to be connected to an external electrical supply line, so that the at least one fixed contact with the connection part can be connected to an external electrical supply line.

According to a further embodiment, the fastening part has a recess and the connecting part projects into the recess of the fastening part. The recess can particularly preferably be designed as a blind hole, so that the connecting part does not protrude through the fastening part. In particular, the fastening part can be cup-shaped. The fastening part can have a contact surface on a floor area on a side opposite the connecting part, with which the fastening part and thus the at least one fixed contact is in mechanical contact with the movable contact in a switching state of the switching device. The contact surface is thus arranged in the switching chamber. Consequently, the internal mechanical contact described above with the movable contact preferably takes place via the fastening part, whereas the external mechanical contact with an external supply line takes place via the connecting part.

According to a further embodiment, the connection part is outside the switching device accessible. In particular, the connection part can have a connection element that is arranged outside a housing of the switching device. The connection element can be formed, for example, by a stud bolt. The stud bolt particularly preferably has an external thread. Alternatively, the connecting element can, for example, also have or be a threaded hole in the connecting part.

Furthermore, the connecting part can have a support element from which the connecting element extends away. In particular, the connection element can extend away from the support element in a direction facing away from the fastening part. For this purpose, the support element can particularly preferably have an upper side facing away from the switching chamber, from which the connection element protrudes.

The support element can, for example, be designed in the shape of a disk, particularly preferably in the form of a circular disk, from which the connection element, for example in the form of a stud bolt, protrudes centrally. The connection element can be provided for positioning and arrangement as well as for fastening an external electrical supply line. If the connecting element has an external thread, a fastening nut, for example, can be screwed onto the connecting element. The top side of the support element can form a support surface for the external electrical supply line, against which the external electrical supply line is pressed in a fastened state, for example with the fastening nut tightened, in order to achieve the lowest possible electrical contact resistance between the at least one fixed contact and the first electrical to reach the supply line. The external electrical supply line can therefore, for example, have a hole through which the connection element protrudes, and can also be clamped between the support element and a fastening nut screwed onto the connection element.

According to a further embodiment, the connection part has a connecting element. The connecting element is preferably arranged on a side of the support element that is opposite the connecting element. The connecting element can be formed, for example, by a stud bolt. In particular, when viewed from the support element, the connecting element can extend in a direction facing the fastening part. For this purpose, the support element can particularly preferably have an underside facing the switching chamber, from which the connecting element protrudes.

In particular, the connecting element can protrude into the recess of the fastening part and can particularly preferably be arranged in the recess. The connecting part can particularly preferably be screwed into the recess with the connecting element. For this purpose, the connecting element can have an external thread and the recess in the fastening part can have an internal thread. Particularly preferably, the connecting element and the connecting element can each have an external thread with the same thread size.

According to a further embodiment, the external thread of the connecting element and/or the internal thread of the recess have an interference fit before the connecting part is screwed into the fastening part. In other words, the internal thread of the recess is tolerated to be smaller than the external thread of the connecting element. The threads preferably correspond to the standards DIN 13-1 to DIN 13-52, particularly preferably DIN 13-51 (transition tolerance field for a sealing fit). For example, there may be a fit “M8 - 5H/4h” (transitional fit). The standards according to DIN 13 usually refer to fine threads such as threads of type M6, M8 etc. Other thread types are also included, for example non-metric thread types, for example according to ASME B1.1, and special threads, for example according to DIN 7756 and valve threads. By screwing the connecting element into the recess, a tighter screw connection can be achieved due to the oversize, which can prevent the connecting part from being unintentionally unscrewed from the fastening part.

According to a further embodiment, a connecting material is arranged between the external thread of the connecting element and the internal thread of the recess. The connecting material can have an adhesive or be an adhesive, for example with or made from an acrylate such as a methacrylate or a cyanoacrylate.

According to a further embodiment, a connecting material is arranged in the recess below the connection element. For this purpose, the recess can particularly preferably have a depth that is greater than a height of the connecting element measured from the underside of the support element, so that when the connecting part is completely screwed into the fastening part, a cavity remains below the connecting element in which the connecting material can be arranged . The connecting material can have an adhesive, for example an adhesive described above, or a soft solder or made from it be. A soft solder is referred to here and below as a solder that preferably has a melting point of less than or equal to 400 ° C. The soft solder can be arranged, for example, in the form of a solder pill in the recess of the fastening part that is already attached to the switching chamber. After screwing in the connecting part, the soft solder can be melted by heating, for example in an oven. The soft solder can be free of fluxes. Alternatively, the soft solder can be provided with a flux. For example, the wetting properties of the soft solder can be improved using a flux. The soft solder can preferably be lead-free. For example, the soft solder can contain or be made from one or more materials selected from bismuth (Bi), tin (Sn) and antimony (Sb). The proportions, based on the mass, can, for example, for bismuth and tin each be greater than or equal to 25% and less than or equal to 35% and particularly preferably greater than or equal to 27% and less than or equal to 31% and for antimony greater than or equal to 50% and less or equal to 70% and particularly preferably greater than or equal to 38% and less than or equal to 46%. Furthermore, the soft solder can, for example, contain or be made from one or more materials selected from tin (Sn), silver (Ag) and copper (Cu). For tin, for example, the proportions, based on the mass, can be greater than or equal to 50% and particularly preferably greater than or equal to 85%. The proportions based on the mass of silver can be less than 15% and preferably less than 5%. The proportions, based on the mass, of copper can be less than 5% and preferably less than 1%. For example, the soft solder can be Sn96.5Ag3.0Cu0.5.

According to a further embodiment, the underside of the support element rests on the fastening part. The fastening part can have an edge region with an upper side on which the underside of the support element rests. The edge region can particularly preferably be formed all around the recess in the fastening part.

According to a further embodiment, a connecting material is arranged between the underside of the support element and the top of the edge region. For example, the connecting material can have or be a soft solder, for example a soft solder as described above.

According to a further embodiment, the top of the edge region of the fastening part and/or the underside of the support element of the connecting part has a surface structure, for example knurling and/or roughening. The surface structure can particularly preferably be provided in conjunction with a connecting material between the underside of the support element and the top of the edge region.

According to a further embodiment, the support element is welded to the edge region. In particular, the support element can be connected to the edge region by means of a weld seam on an outside of the contact region, which is formed by the underside of the support element and the top side of the edge region, wherein the weld seam can particularly preferably be completely circumferential.

The attachment of the connecting part to the fastening part can be improved by one or more of the connecting materials mentioned and/or the surface structure and/or the welding. This can reduce or even prevent the risk of the connecting part coming loose from the fastening part.

The support element and the edge region can particularly preferably have the same outside diameter. The top of the edge region and the bottom of the support element can, for example, both be annular and arranged congruently with one another. Furthermore, the support element and the edge region can each be partially arranged in an opening in a housing of the switching device. In particular, the contact area between these, i.e. the top of the edge area and the underside of the support element, can be arranged within the opening of the housing.

According to a further embodiment, the edge region has a fastening edge facing the switching chamber, which is cohesively connected to the switching chamber. In other words, the fastening edge is arranged opposite the top side. In particular, the fastening edge can be connected to the switching chamber by means of a hard solder, whereby the at least one fixed contact is fastened to the switching chamber. The switching chamber can have a corresponding edge region all around the opening through which the at least one fixed contact, i.e. in particular the fastening part, protrudes into the switching chamber, which can be formed, for example, by a raised ring structure and on which the fastening edge is fastened by means of the brazing . Here and below, a braze is referred to as a solder that has a melting point of greater than or equal to 600 ° C. A solder based on silver and/or can be used as a hard solder, for example Copper can be used, particularly preferably a silver-copper alloy such as Ag72Cu28.

According to a further embodiment, the connecting part and the fastening part are made of the same material. In particular, the connection part and the fastening part can each have or be made from a material generally mentioned above for the contacts, for example a metal, preferably copper or a copper alloy. When installed, i.e. when the at least one fixed contact is attached to the switching chamber, the fastening part can have a lower hardness than the connecting part. This can be done by soldering the fastening part to the switching chamber using the brazing solder. Due to the typically high temperature of, for example, 800 ° C or more during brazing, the material of the fastening part can be softer after brazing than before due to solid-state physical processes. The connecting part, on the other hand, can retain its original hardness because it is not subjected to a brazing process but is screwed in after brazing.

In the switching device described here, one or more fixed contacts, which form the attachment points for external electrical supply lines, are designed in two parts, with only one, preferably small, part of each of the fixed contacts actually being soldered in by means of brazing and a second part, which involves the soldering process not passed through, will be added later. This has the advantage that there is no weight disadvantage compared to conventional one-piece contacts, the contact resistance does not increase or increases only slightly due to the same materials, and increased mechanical strength is still achieved compared to one-piece fixed contacts. Through the measures described above, the second part can be securely attached to the soldered first part. As a result, the fixed contacts and the switching device described here can be produced inexpensively with little or no increased process costs and, compared to one-piece fixed contacts, higher mechanical loads are possible.

• 1A und 1B zeigen schematische Darstellungen eines Ausführungsbeispiels für eine Schaltvorrichtung,
• 2A bis 2E zeigen schematische Darstellungen eines feststehenden Kontakts der Schaltvorrichtung und
• 3A und 3B zeigen schematische Darstellungen eines Verfahrens zur Montage eines feststehenden Kontakts am Schaltkammerdeckel der Schaltvorrichtung gemäß einem weiteren Ausführungsbeispiel,
• 4 bis 8B zeigen schematische Darstellungen eines feststehenden Kontakts der Schaltvorrichtung gemäß weiteren Ausführungsbeispielen.

Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described below in connection with the figures.

• 1A and 1B show schematic representations of an exemplary embodiment of a switching device,
• 2A until 2E show schematic representations of a fixed contact of the switching device and
• 3A and 3B show schematic representations of a method for mounting a fixed contact on the switching chamber cover of the switching device according to a further exemplary embodiment,
• 4 until 8B show schematic representations of a fixed contact of the switching device according to further exemplary embodiments.

In the exemplary embodiments and figures, identical, similar or identically acting elements can each be provided with the same reference numerals. The elements shown and their size ratios to one another are not to be viewed as true to scale; rather, individual elements, such as layers, components, components and areas, may be shown exaggeratedly large for better display and/or understanding.

In the 1A and 1B An exemplary embodiment of a switching device 100 is shown, which can be used, for example, for switching strong electrical currents and / or high electrical voltages and which can be a relay or contactor, in particular a power contactor. In 1A a three-dimensional sectional view is shown with a vertical sectional plane.

In 1B is the one in 1A marked section BB shown enlarged. The geometries shown are only intended to be exemplary and not restrictive and can also be designed alternatively.

The switching device 100 has contacts 2, 4 in a housing 1, which are also referred to below as switching contacts. The housing 1 serves primarily as a contact protection for the components arranged inside and has or is made of a plastic, for example PBT or glass fiber-filled PBT. In the example shown, the switching device 100 has two fixed contacts 2 as contacts and a movable contact mounted on an insulator 3 in the form of a contact bridge 4. The contact bridge 4 is designed as a contact plate. The fixed contacts 2 together with the contact bridge 4 form the switching contacts. As an alternative to the number of contacts shown, other numbers of contacts, i.e. other numbers of fixed and/or movable contacts, may also be possible. The fixed contacts 2 and/or the contact bridge 4 can, for example, be made with or made of Cu, a Cu alloy or a mixture, for example, of copper with at least one other metal, for example Wo, Ni and/or Cr.

In 1A the switching device 100 is shown in a switched-off state, in which the contact bridge 4 is spaced from the fixed contacts 2, so that the contacts 2, 4 are galvanically isolated from one another. In order to put the switching device 100 into a switched-on state, the contact bridge 4 must be moved upwards in the direction of the fixed contacts 2 in the illustration shown until the contact bridge 4 is in mechanical contact with the fixed contacts 2. In the exemplary embodiment shown, the switching device 100 has a magnetic drive with a movable magnet armature 5, which essentially carries out the switching movement. The magnet armature 5 has a magnetic core 6, for example with or made of a ferromagnetic material. Furthermore, the magnet armature 5 has an axis 7, which is guided through the magnetic core 6 and is firmly connected to the magnetic core 6 at one axis end. At the other end of the axis opposite the magnetic core 6, the magnet armature 5 has the contact bridge 4. The axis 7 can preferably be made with or from stainless steel.

To electrically isolate the contact bridge 4 from the axis 7, the insulator 3, which can also be referred to as a bridge insulator, is arranged between them. To support the compensation of possible height differences and to ensure sufficient mechanical contact between the fixed contacts 2 and the contact bridge 4, a contact spring 34 is arranged below the contact bridge 4, which is supported on the insulator 3 and which exerts a force in the direction of the fixed contacts 2 on the Contact bridge 4 exerts.

The magnetic core 6 is surrounded by a coil 8. A current flow in the coil 8 that can be switched on from the outside by a control circuit generates a movement of the magnetic core 6 and thus of the entire magnet armature 5 in the axial direction until the contact bridge 4 contacts the fixed contacts 2. In the illustration shown, the magnet armature 5 moves upwards for this purpose. The magnet armature 5 thus moves from a first position, a rest position, which corresponds to the separating, i.e. non-switching and thus switched off state, into a second position which corresponds to the active, i.e. switching through and therefore switched on state. In the active state, the switching contacts are galvanically connected to each other.

To guide the axis 7 and thus the magnet armature 5, the switching device 100 has a yoke 9, which can have or be made of pure iron or a low-doped iron alloy and which forms part of the magnetic circuit. The yoke 9 has an opening in which the axis 7 is guided. Furthermore, for example, a guide sleeve (not shown) can be present in the opening of the yoke 9. If the current flow in the coil 8 is interrupted, the magnet armature 5 is moved back into the first position by one or more springs 10. In the illustration shown, the magnet armature 5 thus moves downward again. The switching device 100 is then back in the idle state in which the contacts are open.

For example, when the switching contacts are opened, at least one arc can occur, which can damage the contact surfaces of the switching contacts. This can result in the risk that the switching contacts will “stick” to one another due to welding caused by the arc and will no longer be able to be separated from one another. The switching device 100 is then still in the switched-on state, although the current in the coil 8 is switched off and the load circuit would therefore have to be disconnected. In order to prevent the formation of such arcs or at least to support the extinguishing of arcs that occur, the switching contacts can be arranged in a gas atmosphere, so that the switching device 100 can be designed as a gas-filled relay or gas-filled contactor. In particular, the switching contacts are arranged within a switching chamber 11, for example formed by a switching chamber cover 12 and a switching chamber base 13, in a gas-tight region 14 formed by a hermetically sealed part, the switching chamber 11 being able to be part of the gas-tight region 14. The gas-tight area 14 completely surrounds the magnet armature 5 and the switching contacts, except for parts of the fixed contacts 2 intended for the external connection. The gas-tight area 14 and thus also the interior 15 of the switching chamber 11 are filled with a gas. The gas-tight area 14 is essentially formed by parts of the switching chamber 11, the yoke 9 and additional walls. The gas, which can be filled into the gas-tight region 14 through a gas filler neck 17 as part of the production of the switching device 100, can particularly preferably contain hydrogen, for example with 20% or more H ₂ in an inert gas or even with 100% H ₂ , as gas containing hydrogen can promote the extinguishing of arcs. Furthermore, so-called blowing magnets, i.e. permanent magnets 16, can be present inside or outside the switching chamber 11, which cause an extension of the arc path and can thus improve the extinguishing of the arcs.

The switching chamber cover 12 and the switching chamber base 13 can, for example, be made with or made of a ceramic material such as a metal oxide, for example Al ₂ O ₃ , can be made. Furthermore, plastics with a sufficiently high temperature resistance, for example a PEEK, a PE and/or a glass fiber-filled PBT, are also suitable, for example for the switching chamber base 13. Alternatively or additionally, the switching chamber 11 can at least partially also have POM, in particular with the structure (CH ₂ O) _n . Such a plastic can be characterized by a comparatively low carbon content and a very low tendency to form graphite. Due to the same proportions of carbon and oxygen, especially in (CH ₂ O) _n , predominantly gaseous CO and H ₂ can be formed during decomposition induced by heat and in particular by arc. The additional hydrogen can increase arc extinction. Particularly preferred are the switching chamber cover 12 made of a ceramic material and the switching chamber base 13 made of a ceramic material or a plastic as described above.

The fixed contacts 2 are arranged in openings 121 of the switching chamber cover 12 and protrude through the openings 121 into the interior 15 of the switching chamber 11, so that in particular the contact surfaces 208 of the fixed contacts 2 are arranged in the interior 15 of the switching chamber 11. The fixed contacts 2 are permanently and in particular gas-tightly mounted in a materially bonded manner on a mounting area 122 of the switching chamber cover 12 that runs around the openings 121. The fixed contacts 2 are particularly preferably mounted on the switching chamber 11 by brazing. For this purpose, the fixed contacts 2, which have a fastening part 20 and a connecting part 21, have an edge region 203 with a fastening edge 205, between which and the mounting region 122 a hard solder (not shown) is arranged. For example, a solder based on silver and/or copper can be used as the hard solder, particularly preferably a silver-copper alloy such as Ag72Cu28. Procedural steps of a method for mounting the fixed contacts 2 on the switching chamber cover 12 are in connection with 3A and 3B described.

To connect the fixed contacts 2 to external electrical supply lines (not shown) of a load circuit, they protrude, as shown in FIG 1A and 1B is indicated, through openings 101 in the housing 1 and have connection elements 211 outside the housing 1, which are designed, for example, as so-called stud bolts, to which external supply lines such as supply rails, so-called bus bars, or cable lugs are mounted. The connection elements 211 can, as explained in connection with the following figures, have a thread, so that the external supply lines can be fixed, for example by means of screw nuts, on the connection elements 211 and thus on the fixed contacts 2 and pressed against support elements 213. In order to achieve the lowest possible electrical contact resistance between the external supply lines and the fixed contacts 2 and to ensure a permanent mechanical connection, even with shear forces and lever forces that can occur during operation, a sufficiently high tightening torque is necessary with which the screw nuts be screwed onto the connecting elements 211. Therefore, the connection elements 211 in particular must have sufficient mechanical strength. In other words, the material of the connecting elements 211 must be sufficiently hard. However, as described at the beginning, in the case of a conventional fixed contact, the brazing process for attaching the fixed contact would lead to a change and in particular softening of the material.

The fixed contacts 2 are therefore designed in two parts in the switching device 100 shown. Further features and embodiments of the fixed contacts 2 are explained in connection with the following figures.

In the 2A until 2E are different views of a fixed contact 2 corresponding to the two fixed contacts 2 of the switching device 100 according to the exemplary embodiment of 1A and 1B shown. In other words, the fixed contacts 2 of the switching device 100 can be like the fixed contact 2 according to the description of 2A until 2E be trained. In the 2A and 2 B a three-dimensional top view and a three-dimensional sectional view of the fixed contact 2 are shown. The 2C until 2E show various further sectional views of the fixed contact 2 or parts of it. The following description also refers to the 2A until 2E .

As in connection with the 1A and 1B described, the fixed contact 2 has two parts, formed by a fastening part 20 and a connecting part 21, which, when put together, essentially form the at least one fixed contact 2 and which are permanently joined together in the switching device. Particularly preferably, the connecting part 21 and the fastening part 20 are connected to one another at least in a form-fitting and/or non-positive manner, for example by a clamp connection or, particularly preferably by a screw connection. Furthermore, the connecting part 21 and the fastening part 20 can also be cohesively connected to one another who be connected, as in connection with the 4 until 8B is described.

The fastening part 20 is intended and set up to be attached to the switching chamber as in connection with the 1A and 1B described to be fastened by means of brazing, so that the fixed contact 2 is fastened to the switching chamber with the fastening part 20. The connecting part 21 is, as in connection with the 1A and 1B is described, intended and set up to be connected to an external electrical supply line, so that the fixed contact 2 with the connecting part 21 can be connected to an external electrical supply line.

The fastening part 20 has a recess 200 and the connecting part 21 projects into the recess 200 of the fastening part 20. The depression 200 is designed as a blind hole, so that the connecting part 21 does not protrude through the fastening part 20. In particular, the fastening part 20 can be cup-shaped with a bottom area 201 and an adjoining wall area 202. On the bottom area 201, the contact surface 208 is provided on a side opposite the connecting part 21.

The connecting part 21 has the connecting element 211 designed as a stud bolt, which, as in the 1A and 1B is shown, is arranged outside the housing of the switching device and has an external thread 212. The connection element 211 extends from a top side 214 of the support element 213 in a direction facing away from the fastening part 20. The support element 213 is, as in 2A recognizable, particularly preferably disc-shaped, particularly preferably in the form of a circular disc, from which the connecting element 211 protrudes centrally.

Furthermore, the connecting part 21 has a connecting element 216. The connecting element 216 is arranged on a side of the support element 213 opposite the connection element 211 and is designed as a stud bolt which protrudes from an underside 215 of the support element 213 facing the switching chamber, so that the connecting element 216, when viewed from the support element 213, is in a direction towards the fastening part 20 facing direction extends.

The connecting element 216 projects into the recess 200 of the fastening part 20 and is arranged in this. The connecting part 21 is screwed into the recess 200 with the connecting element 216. For this purpose, the connecting element 216 has an external thread 217. The recess 200 in the fastening part 20 has a matching internal thread 207 in the wall area 202. For example, the connecting element 211 and the connecting element 216 can each have an external thread 212, 217 with the same thread size, approximately size M8. In particular, the external threads 212, 217 can have the same direction of rotation and can therefore both be right-hand threads, for example.

Furthermore, the external thread 217 of the connecting element 216 and/or the internal thread 207 of the recess 200 can have an interference fit as described above in the general part before screwing the connecting part 21 into the fastening part 21, whereby a tighter screw connection can be achieved, which prevents unintentional unscrewing of the connecting part 21 from the fastening part 20 can be prevented.

After screwing in the connecting part 21, the support element 213 lies with the underside 215 preferably on the fastening part 20. For this purpose, the fastening part 20 can in particular have the edge region 203 with an upper side 204 on which the underside 215 of the support element 211 rests, so that the best possible electrical contact between the fastening part 20 and the connecting part 21 can be achieved. The edge region 203 can particularly preferably be formed all around the recess 200 in the fastening part 20.

The support element 211 and the edge region 203 can particularly preferably have the same outside diameter. The top 204 of the edge region 203 and the bottom 215 of the support element 211 can, for example, both be annular and arranged congruently on one another. Like in the 1A and 1B can be seen, the support element 211 and the edge region 203 can each be partially arranged in the opening in the housing of the switching device. In particular, the contact area between these, i.e. the top 204 of the edge area 203 and the bottom 215 of the support element 213, can be arranged within the opening of the housing.

As in connection with the 1A and 1B is described, the edge region 203 has a fastening edge 205 facing the switching chamber, which is cohesively connected to the switching chamber. The fastening edge 205 can be spaced from the wall area 202, for example by a circumferential channel 204. In the 3A and 3B Method steps of a method for mounting the fixed contact 2 on the switching chamber cover 12 are shown, which apply to all fixed contacts 2 within the scope of Production of the switching device can be carried out.

As in 3A is shown, the fastening part 20 is inserted into the opening 121 of the switching chamber cover 12 so that the fastening edge 205 is arranged on the mounting area 122. The mounting area 122 can be formed, for example, in an edge area of the opening 121 by a raised ring structure. A hard solder 120 is applied between the mounting area 122 and the fastening edge 205, for example a solder based on silver and/or copper and particularly preferably a silver-copper alloy such as Ag72Cu28. The switching chamber cover 12 can be heated with the fastening parts 20 of all fixed contacts 2 arranged in this way, for example in an oven, so that a gas-tight connection is created between the switching chamber cover 12 and the fastening parts 20 by the melting and re-solidifying braze 120. Then, as in 3B is indicated, a connecting part 21 can be screwed into each fastening part 20.

Particularly preferably, the connecting part 21 and the fastening part 20 are made of the same material, for example with or made of a metal, preferably oxygen-free copper or a copper alloy. In the installed state, i.e. when the fixed contact 2 is attached to the switching chamber, the fastening part 20 can have a lower hardness than the connecting part 21 due to the brazing process. Due to the typically high temperature of, for example, 800 ° C or more during brazing, the material of the fastening part 20 can be softer after brazing than before due to solid-state physical processes. The connecting part 21, on the other hand, can retain its original hardness since it is not subjected to a brazing process but is screwed in after brazing.

While the fastening part 20 is soldered to the switching chamber cover and can become softer in the process, the connecting part 21 made of the same material remains untreated because it is only attached afterwards. The cross section of the 2E The recognizable T-shape of the harder connecting part 21 promotes the frictional connection with the fastening part 20 and prevents shear forces, which can later act on the connecting element 211, from damaging the internal thread 207 of the fastening part 20 via a leverage effect. It has been shown that even with a relatively low tightening torque of approximately 4 Nm, the electrical contact resistance added by the two-part shape of the fixed contact 2 is negligible.

In the following 4 until 8B Further developments of the fixed contact 2 are shown according to further exemplary embodiments, which can improve a permanent connection between the fastening part 20 and the connecting part 21. For clarity are in the 4 until 8B only the elements described are provided with reference numbers. The measures described can be used alone or in combination.

As in 4 is shown, a connecting material 23 can be arranged between the external thread 217 of the connecting element 216 of the connecting part 21 and the internal thread 207 of the recess 200 of the fastening part 20, as indicated by the dashed areas. The connecting material 23 can have an adhesive or be an adhesive, for example with or made of an acrylate such as a methacrylate or a cyanoacrylate. The adhesive can harden after mounting the connecting part 21 on the fastening part 20 and prevent the connecting part 21 from being unscrewed unintentionally.

As in 5 is shown, a connecting material 24 can be arranged in the recess 200 below the connecting element 216 of the connecting element 21. For this purpose, the recess 200 particularly preferably has a depth which is greater than a height of the connecting element 216 measured from the underside 215 of the support element 213, so that when the connecting part 21 is completely screwed into the fastening part 20, a cavity remains below the connecting element 216, in which the connecting material 24 can be arranged. The connecting material 24 can have or be made of an adhesive, for example an adhesive described above, or particularly preferably a soft solder. The soft solder can be arranged, for example, in the form of a solder pill in the recess 200 of the fastening part 20, which is already attached to the switching chamber. After screwing in the connecting part 21, the soft solder can be melted by heating, for example in an oven, whereby the temperature required for this is significantly lower than in the brazing process and does not result in any softening of the connecting part 21. The soft solder can preferably be lead-free and, for example, based on Bi, Sn and/or Sb or based on Sn and Ag and/or Cu, as described above in the general part. The soft solder can be free of flux so that no flux residue remains in the cavity. Alternatively, the soft solder can be provided with a flux. For example, the wetting properties of the soft solder can be improved using a flux.

As in 6 is shown, a connecting material 25 can be arranged between the bottom 215 of the support element 213 of the connecting part 21 and the top 204 of the edge region 203 of the fastening part 20. For example, the connecting material 25 can have or be made of an adhesive or, particularly preferably, a soft solder according to the previous description.

For those in the 5 and 6 The developments shown can therefore, before the connecting part 21 is screwed onto the fastening part 20, a connecting material 24, 25, particularly preferably in the form of a soft solder, either close to the thread in the recess 200 or on the outer edge, i.e. on the through the top 204 of the edge region 203 formed support surface, are applied. For example, after assembly of the connecting part 21, a solder containing a flux can be brought to its melting temperature, which is preferably less than or equal to 300 ° C, which leads to melting and subsequently to a solid connection. The low melting temperature of the soft solder avoids a reduction in the hardness of the connecting part 21, since this would typically only occur with copper and copper alloys at temperatures of more than 500 ° C. During operation of the switching device, the temperatures of the fixed contact 2 typically remain at less than 160 ° C, which prevents the soft solder from melting again. The introduction of the connecting material 25 on the outer edge has the advantage that it increases the torque required to release the soft solder connection.

Furthermore, as in the 7A and 7B is shown, the top 204 of the edge region 203 of the fastening part 20 and / or the underside 215 of the support element 213 of the connecting part 21 have a surface structure 209, 219, for example a knurling and / or a roughening, which can be produced, for example, by sandblasting. The surface structure 209, 219 can particularly preferably be provided in conjunction with a connecting material 25 between the underside 215 of the support element 213 and the upper side 204 of the edge region 203.

Like in the 8A and 8B is shown, the support element 213 of the connecting part 21 can be welded to the edge region 203 of the fastening part 20. After screwing the connecting part 21 to the fastening part 20, the contact edge is welded all around or partially on the edge. In particular, the support element 213 can be connected to the edge region 203 by means of a weld seam 26, which is in 8A indicated by the dashed area, are connected to one another on an outside of the contact area, which is formed by the underside 215 of the support element 213 and the top 204 of the edge area 203, wherein the weld seam 26 can particularly preferably be completely circumferential. The weld seam 26 can particularly preferably be formed by laser welding. Welding has the advantage of a short process time. Furthermore, a high level of security against unintentional detachment of the connecting part 21 from the fastening part 20 can be achieved during use of the switching device.

The surfaces of the parts to be joined can be prepared in such a way that laser beams can effectively introduce energy and reflection of the beams can be prevented. As in 8B is indicated, an absorption element 27 can be arranged in the welding area, which can be formed, for example, by a suitable paint, a varnish or a roughening.

The features and exemplary embodiments described in connection with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures can alternatively or additionally have further features according to the description in the general part.

The invention is not limited to these by the description based on the exemplary embodiments. Rather, the invention encompasses every new feature and every combination of features, which in particular includes every combination of features in the patent claims, even if this feature or this combination itself is not explicitly stated in the patent claims or exemplary embodiments.

Reference symbol list

1

Housing

2

fixed contact

3

insulator

4

Contact bridge

5

Magnetic anchor

6

magnetic core

7

axis

8th

Kitchen sink

9

yoke

10

Feather

11

switching chamber

12

Switching chamber cover

13

Switching chamber floor

14

gas-tight area

15

inner space

16

Permanent magnet

17

Gas filler neck

20

Fastening part

21

Connection part

23, 24, 25

connecting material

26

Weld

27

Absorbent element

28

Laser light

34

Contact spring

100

Switching device

101, 121

opening

122

Assembly area

123

Fastening edge

120

Hard solder

200

deepening

201

floor area

202

Wall area

203

Edge area

204

Top

205

Fastening edge

206

gutter

207

inner thread

208

Contact surface

209

Surface structure

211

Connection element

212

External thread

213

Support element

214

Top

215

bottom

216

connecting element

217

External thread

219

Surface structure

Claims (13)

Switching device (100), having at least one fixed contact (2) which projects into a switching chamber (11), wherein - the at least one fixed contact (2) has a fastening part (20) and a connecting part (21), - the fastening part (20) is attached to the switching chamber (11) and - the connecting part (21) projects into a recess (200) of the fastening part (20), the switching device (100) having one or more of the following features: - the connecting part (21) and the fastening part (20) are made of the same material, the fastening part (20) having a lower hardness than the connecting part (21); - The connection part (21) has a connection element (211), which is arranged outside a housing (1) of the switching device (100) and is formed by a stud, and a support element (213) from which the connection element (211) is extends away and which has an underside (215) facing the switching chamber (11), with which the connecting part (21) rests on the fastening part (20), and the fastening part (20) has an edge region (203) with an upper side (204). , on which the underside (215) of the support element (213) rests, where A connecting material (25) which has a soft solder is arranged between the bottom (215) of the support element (211) and the top (204) of the edge region (203), and/or the support element (211) is welded to the edge region (203) and/or the edge region (203) has a fastening edge (205) facing the switching chamber (11), which is cohesively connected to the switching chamber (11); - The connecting part (21) projects into the recess (200) of the fastening part (20) with a connecting element (216) and is screwed into the recess (200) with the connecting element (216), the connecting element (216) having an external thread ( 217) and the recess (200) in the fastening part (20) have an internal thread (207) and the external thread (217) and/or the internal thread (207) have an interference fit before screwing the connecting part (21) into the fastening part (20). having; - A connecting material (24) which has a soft solder is arranged in the recess (200) below the connection element (211). Switching device (100). Claim 1 , wherein the fastening part (20) is cup-shaped and the recess (200) is designed as a blind hole. Switching device (100). Claim 1 or 2 , wherein the top (204) of the edge region (203) of the fastening part (20) and / or the bottom side (215) of the support element (213) of the connecting part (21) has a surface structure (209, 219). Switching device (100). Claim 3 , wherein the surface structure (209, 219) has knurling and / or roughening. Switching device (100) according to one of the preceding claims, wherein the support element (213) is connected to the edge region (203) by means of a weld on an outside of the contact region, which passes through the bottom (215) of the support element (213) and the top (204) of the Edge region (203) is formed, are connected to each other. Switching device (100). Claim 5 , whereby the weld seam is completely circumferential. Switching device (100) according to one of the preceding claims, wherein in the recess (200) below the connection element (211) there is a cavity in which the connecting material (24) is arranged. Switching device (100) according to one of the preceding claims, wherein - the soft solder of the connecting material (24) contains bismuth, tin and antimony, - Bismuth and tin each have a proportion, based on mass, of greater than or equal to 27% and less than or equal to 31% and - Antimony has a proportion, based on mass, of greater than or equal to 38% and less than or equal to 46%. Switching device (100) according to one of the Claims 1 until 7 , whereby - the soft solder of the connecting material (24) has tin, silver and copper, - tin has a proportion, based on the mass, of greater than or equal to 50%, - silver has a proportion, based on the mass, of less than or equal to 15 % and - copper has a proportion, based on the mass, of less than or equal to 5%. Switching device (100) according to the previous claim, wherein the soft solder is Sn96.5Ag3.0Cu0.5. Switching device (100) according to one of the preceding claims, wherein a connecting material (23) which has an adhesive is arranged between the external thread (217) and the internal thread (207). Switching device (100) according to one of the preceding claims, wherein the switching device (100) has a housing (1) in which the switching chamber (11) is arranged, and the top (204) of the edge region (203) and the bottom (215) of the support element (213) are arranged within an opening (101) of the housing (1). Switching device (100) according to one of the preceding claims, wherein the top (204) of the edge region (203) and the underside (215) of the support element (213) are both annular and are arranged congruently one on top of the other.

Images